Coffee filter paper: the guardian of pure extraction

Coffee filter paper, seemingly simple, plays a vital role in the coffee extraction process. It is like an unknown guardian, filtering out impurities in coffee powder and bringing us a cup of clear and pure coffee.

Working principle

The working principle of coffee filter paper is mainly based on physical filtration and adsorption:

Physical filtration: Coffee filter paper is composed of criss-crossing fibers, forming countless tiny pores. When hot water passes through coffee powder, the soluble substances in the coffee powder (caffeine, aromatic substances, etc.) will dissolve in the water and flow into the cup through the pores of the filter paper. The insoluble substances in the coffee powder (coffee grounds, oils, etc.) will be blocked by the filter paper, thereby separating the coffee liquid from the coffee grounds.

Adsorption: The fiber surface of the coffee filter paper has a certain adsorption capacity, which can adsorb some coffee oils and fine particles, further improving the purity of the coffee.

Common materials

The materials of coffee filter paper are mainly divided into the following categories:

1. Wood filter paper: This is the most common type of coffee filter paper. It is made of virgin wood pulp, has good air permeability and filtration performance, and can retain the aroma and flavor of coffee.

2. Hemp filter paper: Hemp filter paper is made of natural hemp fiber, which is more environmentally friendly than wood filter paper, and the fiber is coarser and the filtration speed is faster. It is suitable for coffee lovers who like a strong taste.

3. Metal filter: The metal filter is made of stainless steel or other metal materials, which can be reused, environmentally friendly and economical. However, the pores of the metal filter are large, and it cannot filter out coffee oil and fine particles, and the coffee tastes relatively turbid.